Sooxiwei, The last amp is growing on a clay cliff. The second last is growing on clay also. Some of the other amp in the picture are growing on sand.
Shamrock, Yes, they're really nice but too bad that they're not genetically fixed that way.
Cjloong, They're found in sunny area but some in shade also (pic 5). I've tried placing my cultivated amp in full sun but it didn't change colour.
I've found a wild raff with pink tint also. So, I think it could be due to sudden change of temperature.
Yes, We met at Fauzi's stall. Nice to meet you.